This invention relates to new salicyl alcohol derivatives, to processes for their preparation and to cosmetic and/or pharmaceutical preparations containing these compounds.
Many naturally occurring alkyl and phenol glucosides show antiviral, antimicrobial and, in some cases, anti-inflammatory effects (S. Matsamura, K. Imai, K. Kawada and T. Uchibori, Surface activities, biodegradability and antimicrobial properties of n-alkyl-glucosides, mannosides and galactosides, J. Am. Oil Chem. Soc. 67, 996-1001 (1990); T. Hedner and B. Everts, The early clinical history of salicylates in rheumatology and pain, Clin. Rheumatol. 12, 17-25 (1998)). Above all, aqueous extracts of willow bark (Salix alba, purpurea or fragilis) and poplar are known to have anti-inflammatory activity. Accordingly, corresponding extracts are used in medicinal teas and in cosmetic products, for example to reduce irritation of the skin, as described in German patent application DE 196 15 577. Important ingredients of willow bark include salicin and salicylic acid (o-hydroxybenzoic acid), salicortin (2-[[[(1-hydroxy-6-oxo-2-cyclohexen-1-yl)-carbonyl]oxy]methyl]phenyl-xcex2-D-glucopyranoside) and fragilin (acetyl salicin) while the bark of poplars contains populin (benzoyl salicin). In the main, salicylic acid and its derivatives, such as acetyl salicylic acid, have been very thoroughly investigated for anti-inflammatory activity. As non-steroidal anti-inflammatory drugs (NSAID), they inhibit prostaglandin synthesis (J. R. Vane, Inhibition of prostaglandin synthesis as a mechanism of action of the aspirin-like drugs, Nature, 231, 232-235 (1971)).
Prostaglandins are formed as a reaction to various exogenous cell-specific stimuli by deoxygenation of polyunsaturated fatty acids, more particularly arachidonic acid, catalyzed by the enzymes prostaglandin-synthase-1 and -2 (PGHS-1 and -2). As autocrinal and paracrinal tissue hormones, they are formed to a greater extent in cases of injury or skin irritation, in wound healing processes and in inflammatory reactions.
Normal epidermis already contains significant quantities of prostaglandins which are evidently formed by PGHS-1 because PGHS-2 is not expressed. In irritated skin, prostaglandins (above all PGE2 and PGF27 from the keratinocytes) as local inflammation mediators promote both the dilation (widening) and also greater permeability of blood vessels and are thus involved in the reddening, heating and swelling of the skin typical of inflammation reactions (G. Fxc3xcrstenberger, Role of eisosanoids in mammalian skin epidermis, Cell. Biol. Rev. 24, 1-90 (1990); G. Fxc3xcrstenberger, V. Kinzel, M. Schwarz and F. Marks, Partial inversion of the initiation-promotion sequence of multistage tumorigenesis in the skin of NMRI mice; Science 230, 76-78 (1985)) and in the development of a regenerative epidermal hyperplasia. Prostaglandin synthesis inhibitors are capable of preventing these unwanted effects.
Besides the salicin derivatives occurring in willow and poplar mentioned at the beginning, the isolation of benzoyl salicin from plants is known from the literature (L. van Hoof et al., Plant viral agents, VI. Isolation of antiviral phenolic glucosides from Populus cultivar Beaupre by droplet counter-current chromatography, J. Nat. Prod. 52, 875-878 (1989)) as is the enzymatic production of phenyl butyryl salicin (R. T. Otto, U. T. Bornscheuer, C. Syldatk and R. D. Schmid, Lipase-catalyzed synthesis of arylaliphatic esters of D(+)-glucose, alkyl- and aryl-glucosides and characterization of their surfactant propeties; J. Biotechnol. 64, 231-237 (1998)).